Magnesium alloy shell of golf club head made by die casting

ABSTRACT

A shell of a golf club head is made of magnesium alloy and is made by die casting. The golf club head has a top portion, a face, a bottom portion, a toe portion, a heel portion and a neck, which is divided into the shell and a face member along a dividing line. The dividing line crosses the highest portion of the top portion, the peak portion of the toe portion, the bottom portion and the peak portion of the heel portion.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a golf club, and more particularly to a magnesium alloy shell of a golf club head made by die casting.

2. Description of the Related Art

U.S. Pat. No. 5,494,281 taught a golf club head with a shell made of magnesium alloy and a face made of titanium alloy or ceramic. The magnesium alloy has properties of light in weight, shock absorption and cheaper than titanium alloy. The housing is made by die casting for mass production, but it also has a few drawbacks. To facilitate die release, the shell, as shown in FIG. 8 and FIG. 9, is thicker at a crown 91, a toe 92 and a heel 94 that makes the shell heavier. Such shell is no good for a greater size golf club head.

US Patent Publication No. 20040023731 taught a hollow golf club head, which is divided into a front shell and a rear shell. The rear shell may be made of stainless steel, aluminum, magnesium or the alloy thereof. The patent lacks of disclosing how to divide the golf club head, so that it still doesn't provide the solution.

SUMMARY OF THE INVENTION

The primary objective of the present invention is to provide a magnesium alloy shell of a golf club head made by die casting, which wall of the shell has a uniform thickness, such that the shell can be made for greater size golf club head.

According to the objectives of the present invention, a shell of a golf club head is made of magnesium alloy and is made by die casting. The golf club head has a top portion, a face, a bottom portion, a toe portion, a heel portion and a neck, which is divided into the shell and a face member along a dividing line to have the shell with a maximum opening.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a preferred embodiment the present invention;

FIG. 2 is a top view of FIG. 1;

FIG. 3 is a bottom view of FIG. 1;

FIG. 4 is a sketch diagram showing the shell of the preferred embodiment the present invention bonded with a face;

FIG. 5 is a sectional view along 5-5 line of FIG. 4;

FIG. 6 is a top view in part of FIG. 4;

FIG. 7 is a bottom view of FIG. 4, and

FIG. 8 and FIG. 9 are sectional views of the conventional golf club head made by die casting.

DETAILED DESCRIPTION OF THE INVENTION

As shown in FIGS. 1 to 3, a shell 20 of a golf club head 10 of the preferred embodiment of the present invention, which is made of magnesium alloy and is made by die casting, includes a crown 21, a toe 22, a bottom 23, a heel 24 and a neck 25. The shell 20 is hollow with an opening 26 and a slot 27 around the opening 26.

As shown in FIG. 4 to FIG. 7, to release the mold and to have a thinner thickness, the golf club head 10 is set with a dividing line 50 on a highest portion 111 of a top portion 11 thereof. The dividing line 50 crosses a peak portion 121 of a toe portion 12, a bottom portion 13 and a peak portion 141 of a heel portion 14, such that a size of the opening 26 is maximum. As a result, at the step of releasing mold at the end of the die casting process, the core of the mold is released from the shell 20 via the opening 26, and the crown 21, the toe 22, the bottom 23 and the heel 24 of the shell 20 have a uniform thickness.

The shell 20 of the present invention has to be bonded with a face member 30, shown as the dot line in FIGS. 4 to 7, to construct the golf club head 10. The face member 30 may be made of titanium alloy, stainless steel or maraging steel and so on, and may be made by casting or forging. In the present invention, the shell 20 is provided with the slot 27 to be engaged with a protrusion 31 on the face member 30, and adhesion, such as epoxy, is added to bond them.

The thickness of the shell 20 of the present invention is thinner and uniform, so that the shell 20 is applied to the big size golf club head. The shell is provided with a weight device 40 at the bottom portion 13 adjacent to the toe portion 14, as shown in FIG. 5 and FIG. 7, to shift a position of a center of weight of the golf club head.

The bottom portion 13 is flatter so that the location of the dividing line 50 on the bottom portion 13 has less effect on the step of releasing mold. In the present invention, the location of the dividing line 50 is adjacent to the face to have a greater area of the bottom portion, so that the bottom portion may provided with trademark, logo or has a predetermined pattern. As shown in FIG. 5, the crown 21 of the shell 20 is provided with the slot 27, such that it has a greater thickness, but it is a selection of the manufacturers. There are some golf club heads having a flat top portion, in other words, there is no highest portion on the top portion, so that the location of the dividing line has less effect on the step of releasing mold.

The neck may be molded on the shell as a single element, it also may be an independent element bonded to the shell. 

1. A shell of a golf club head, which is made of magnesium alloy and is made by die casting, wherein the golf club head is a hollow element having a top portion, a face, a bottom portion, a toe portion, a heel portion and a neck, and is divided into the shell and a face member along a dividing line to have the shell with a maximum opening.
 2. The shell as defined in claim 1, wherein the neck is molded on the shell as a single element.
 3. The shell as defined in claim 1, wherein the neck is an independent element bonded to the shell.
 4. The shell as defined in claim 1, wherein the shell has a slot at an edge along the dividing line.
 5. The shell as defined in claim 1, wherein the face member is made of titanium alloy. 